Geographical environment of Hangjinqi

Hangjinqi is located in the northwest of Ordos Plateau, bordering Dalat Banner and Dongsheng District in the east, Ejinhoro Banner and Wushen Banner in the

Hangjinqi is located in the northwest of Ordos Plateau, bordering Dalat Banner and Dongsheng District in the east, Ejinhoro Banner and Wushen Banner in the south, and Otog Banner and Bayannaoer City across the Yellow River in the west. It spans the Ordos Plateau and the Hetao Plain, and its geographical coordinates are located at north latitude106 55 ˊ16 〃-109 71438+0608 and 39 22 〃. The climate characteristics of Hangjinqi belong to the typical continental climate of mid-temperate semi-arid plateau, with strong solar radiation, abundant sunshine, drought and little rain, large evaporation, large sandstorm, short frost-free period, freezing at the beginning of 10, thawing in April of the following year, changeable hot and cold seasons, long and cold winter, short and hot summer, rapid heating in spring and remarkable cooling in autumn. Most of the year is controlled by the air currents in Siberia and Outer Mongolia Plateau, with an annual average temperature of 6.8℃, long and cold winters, 101.8℃, extremely low temperature of -32℃, short and warm summers, and an average temperature of 22. 1℃ and extremely high temperature of 38. The average sunshine time for many years is 3 193h.

Hangjinqi has drought and little rain, nine droughts in ten years and spring drought every year. The precipitation in the whole banner decreases from east to west, with an average annual precipitation of 245mm, of which 60% is concentrated in July-September in summer, with an average annual evaporation of 2720mm, relative humidity of 49% and dryness 1.98. The wind speed is generally large, with an average annual wind speed of 3.0m/s, which is common in spring, with a maximum wind speed of 28.7m/s, accompanied by sandstorm weather. The average frost-free period is 155 days, and the soil freezing depth for many years is1.5m. Hangjinqi is located in the northwest of Ordos Plateau, with high terrain in the south and low terrain in the north, high terrain in the east and low terrain in the west. The terrain in the territory is composed of Yellow River alluvial plain, desert, wavy plateau and soft sandstone hills, with obvious zonal distribution law: the alluvial plain on the south bank of the Yellow River in the north, with an average width of about 10km, is flat, with an altitude of1012-1080m, high in the west and low in the east, and Jin Hang. The geological structure is a subsidence graben basin covered with thick spun yarn and clayey Quaternary diluvial-alluvial-lacustrine deposits, with a thickness of several hundred meters. The north-central part is the Kubuqi Desert across the whole banner, with a length of 180km from east to west and a width of 40-70km from north to south, covering an area of 7668.50km2, accounting for 40.54% of the total land area of the whole banner. The altitude is 1040- 1360m, with high in the west and low in the east, and well-developed alluvial sand dunes. The sand source comes from the aeolian deposits blown by the underlying materials in situ, followed by the aeolian deposits in the neighboring areas. The south-central area south of Kubuqi Desert is a hilly area of undulating plateau, and the hills are distributed at the east and west ends. The central part is a wavy high plains with an altitude of1068-1619.5 m, and the hilly areas at the east and west ends are strongly eroded and cut, resulting in serious soil erosion. The elevation of Ulan Prague in Taren Gaole Township in the eastern hilly area is 16 19.5m, which is the highest point of Hangjinqi. The southeast is the edge of Mu Us sandy land, with an altitude of1193-1550m. The sand dunes are mainly fixed and semi-fixed, with few moving sand dunes. Dunes are mainly crescent dunes and crescent dune chains. Kubuqi Desert originates in the west and spans east and west, dividing the whole flag into northern riverside area and southern Liangwai area.

Liangwai: located in the middle of Kubuqi and Mu Us deserts, it belongs to desert and semi-desert grassland; Mainly grasslands and natural forest reserves, with vast grasslands;

Along the Yangtze River: near the south bank of the Yellow River, it belongs to the alluvial plain of the Yellow River, with flat terrain, rich water resources and fertile soil. external

(1) Maokong Team

The Maobulakundui River Basin originates from Snibalggacha, Sini Town, flows through Sini Town and Hangjinnaoer Township, and joins the Yellow River in the north of Longmaoying Village, Hangjinnaoer Township. Most of the areas flowing through belong to hilly areas, with steep ground slope, sparse vegetation and serious soil erosion. The main ditch crosses Kubuqi Desert, with high sediment concentration and frequent floods. Maobulakundui is a feathery basin with a total area of 1260.7km2, located in Hangjinqi 120 1.7km2, in which the hilly and gully region is 752.7km2, which flows through the middle reaches of Kubuqi desert belt with a total area of 425.8km2 and the downstream plain area with a total area of 82.20km2. The length of main ditch 1 10.9km, with an average slope of 4.3‰. The annual average surface runoff is 2859× 104m3, the maximum flood peak discharge is 5600m3/s, the annual average sediment discharge is 2 10× 104 t ... The erosion modulus is from 7000t/km2. The hilly and gully region in South China is 5000t/km2. In the Kubuqi desert in north-central China in. There are 13 tributary basins in Hangjinqi, including 7 on the left and 6 on the right of the main stream, among which there are 5 tributary basins larger than 50km2, namely Gediantaigou, Huojitaigou, Talagou, Ashitugou and Sudal Gully, which are injected into the main stream from the right. Except for Ashitu and Sudal gullies, some of these gullies are located in the southern edge of Kubuqi Desert, and the rest are in hilly gullies. Except for Ergaigou and Kongdui Gullies in gedian, which are wide and arc-shaped with no obvious gullies, all other rivers have gullies, mostly wide U-shaped, a few deep and narrow V-shaped, and most of them are long flowing water.

(2) barragon ditch

Barragon Gully originates from Nulanan, Gus Valley, Bayinger District, barragon Town, and the runoff flows through barragon Town and flows into the Yellow River from the west side of barragon Town. The main ditch is 27.2km long, with a drainage area of 70.4km2. It is a seasonal river with an average annual runoff of 23.23× 104m3 and an average gradient of 12‰, with steep slope and sparse vegetation. Due to the scarcity of rainfall, the ditch dried up after the flood.

(3) Super ditching

Chaokaigou originates from Shangdai Temple in Bayinger area of barragon Town, flows through barragon Town, crosses the main canal on the south bank of the Yellow River at 15km, and flows into the Yellow River. It is a zonal river with a drainage area of 177.6km and a main ditch length of 30.25km. It is a seasonal river with short-term flood in flood season and low water in peacetime, with an average runoff of 53.6× 104m3 for many years.

(4) Other gullies

In addition to the above outflow (Yellow River) water system, there are also some small gullies, which also belong to the outflow water system. Such as Shasugou, Moshigou and Langgou, with a total drainage area of 273km2, mostly in hilly areas. The gully dried up after the flood.

Second, indoor drainage.

(1) Moline River

Moline originates from the Yihe River and the Wusu Sumuxia Hatu spring flow, flows to the southeast and northwest, flows through the whole territory of Sumu, and disappears in the Kubuqi desert in the northwest. The flowing range includes Yaodu, a part of Sumu around Qaidam and most of Bayin Engel, with a drainage area of 5220km2, the length of main ditch of 8 1km, and the average annual runoff of1.93x108m3, of which the basic runoff is 772.6x104m3, accounting for the total runoff. The average river bottom gradient is1.65,438+0 ‰, and the sediment concentration is small, with an annual sediment discharge of 8.4×1.04t. The surface runoff is easy to control and valuable.

(2) Taolaigou

Taolaigou originates from Yaergacha Oil House Beam in Xini Town, flows through Xini Town and Yihe Wusu Sumu, and finally flows into Yanhaizi from Yihe Wusu Sumu. The main ditch is 83.8km long, with an average gradient of 3.3‰, a drainage area of 905.23km2, an average annual runoff of 362.09× 104m3 and a base flow of 144.8× 104 m3.

(3) Yelibaigou

Yelibaigou flows through Xini Town and Hangjinnaoer Village, with a drainage area of 1 19.58 km2 and a main ditch length of 29.7km, with an average gradient of 5.5‰. Desertification is serious in the basin, with short runoff time and long waterless time, and the average runoff for many years is 47.83× 104m3.

(4) Ustu R.

Ustu River passes through Xini Town and Hangjinnaoer Township, with a drainage area of 84.5km2 and a main ditch length of 16.35km, with an average gradient of 4.6‰. Desertification is serious in the basin, with short runoff time and long waterless time. The average runoff for many years is 33.66× 104m3.

(5) Zach waits for the river

Zakdai River originates from Nanwulansu, Xini Town, with a drainage area of 38 1.02km2 and a fan shape. The length of the main river is 16.25km, the average gradient is 1.8‰, and the annual average runoff is152.41×104m3, which flows into the swamp.

(6) Hangedai River

Hangedai River originates from Laowusu, Hangjinnaoer Village Road, with a drainage area of 8 18km2, a main river length of 22. 15km, and an average annual runoff of 327.2× 104m3, which dried up after the flood.

(7) Wujiamiao River

Wujiamiao River originates from Bahantu, Bayinger District, barragon Town, with a drainage area of 59 1.24km2 and a main river length of 32.2km, with an average gradient of 7‰. The annual average runoff195.1×104m3, which caused floods in flood season and dried up after flood season. Due to the regional differences in topography, climate, vegetation and water conditions, the soil in Hangjinqi is distributed in turn from north to south as irrigated tidal soil, aeolian sandy soil and grassland soil zone. The regional distribution of zonal grassland and desert soil from east to west is chestnut soil, brown calcium soil, grey desert soil and brown desert soil. Irrigated and silted fluvo-aquic soil is distributed in the alluvial plain area on the south bank of the Yellow River, with deep soil layer and fertile soil, which is the main soil type for grain production. Chestnut soil is distributed in the hilly depressions and valley terraces on the edge of the undulating plateau and Mu Us sandy land in the southeast, with deep groundwater level and good water quality, and there are processes of humus accumulation and lime deposition. Brown calcium soil is distributed in the wavy plateau area in the south-central part, with a wide distribution area and deep groundwater level. From top to bottom, the soil can be clearly divided into three layers: humus, calcium accumulation and parent material, and the humus layer is light brown. Grey desert soil is distributed in the undulating plateau and hilly area of barragon town in the west, with low soil moisture and organic matter content, desert crust on the surface and gypsum layer in the soil. Aeolian sandy soil is distributed in flag area, Kubuqi desert and Mu Us sandy land are concentrated, and the soil cementation is loose, the soil differentiation is not obvious, and the soil quality is poor, so it is not suitable for farming.

In addition, there are swamp soil and saline soil along the Yellow River and coarse bone soil in Ordos Plateau.